Wheat response to phosphogypsum and mycorrhizal fungi in alkaline soil

Plants grown in alkaline soils often have reduced productivity because of limited mineral nutrients. For plants to obtain adequate nutrients under these conditions, some source of fertilizer is commonly added or a method to make nutrients more available to plants, such as mycorrhiza, is needed. Durum wheat (Triticum turgidum var. durum cv. Petra) was grown in alkaline soil (pH = 8.1) with added phosphogypsum (PG) at different rates [0 (control), 15, 30, 45, and 60g PG kg(-1) dry soil] and the arbuscular mycorrhizal fungus (AMF) Glomus mosseae to determine the effects of these treatments on plant yield and acquisition of phosphorus (P), zinc (Zn), copper (Cu) and iron (Fe). Plants were grown in a greenhouse and harvested at maturity. Colonization of roots with AMF was highest for plants grown without added PG or added at 15 g PG kg(-1) dry soil and decreased as added PG to soil increased. Total plant dry matter and grain yields were enhanced by PG and even more so when roots were colonized with AMF, especially at 30g PG kg(-1) dry soil. Acquisition of P, Cu, and we were higher for mycorrhizal plants grown with 30 g PG kg(-1) soil than for mycorrhizal plants grown with other PG treatments. Results of this study indicate that wheat was dependent on mycorrhizae and responded to an AMF inoculant in soils containing intermediate levels of PG. Therefore, PG can be used as a crude phosphatic fertilizer to ensure satisfactory wheat yields and reduced P fertilization.